Buggy code:
public class LayoutDynamicMBean extends AbstractDynamicMBean { private MBeanConstructorInfo [ ] dConstructors = new MBeanConstructorInfo [ 1 ] ; private Vector dAttributes = new Vector ( ) ; private String dClassName = this . getClass ( ) . getName ( ) ; private Hashtable dynamicProps = new Hashtable ( 5 ) ; private MBeanOperationInfo [ ] dOperations = new MBeanOperationInfo [ 1 ] ; private String dDescription = "This<seq2seq4repair_space>MBean<seq2seq4repair_space>acts<seq2seq4repair_space>as<seq2seq4repair_space>a<seq2seq4repair_space>management<seq2seq4repair_space>facade<seq2seq4repair_space>for<seq2seq4repair_space>log4j<seq2seq4repair_space>layouts." ; private static Logger cat = Logger . getLogger ( LayoutDynamicMBean . class ) ; private Layout layout ; public LayoutDynamicMBean ( Layout layout ) throws IntrospectionException { } private void buildDynamicMBeanInfo ( ) throws IntrospectionException { } private boolean isSupportedType ( Class clazz ) { } public MBeanInfo getMBeanInfo ( ) { } public Object invoke ( String operationName , Object [ ] params , String [ ] signature ) throws MBeanException , ReflectionException { } protected Logger getLogger ( ) { } public Object getAttribute ( String attributeName ) throws AttributeNotFoundException , MBeanException , ReflectionException { } public void setAttribute ( Attribute attribute ) throws AttributeNotFoundException , InvalidAttributeValueException , MBeanException , ReflectionException { if ( attribute == null ) { throw new RuntimeOperationsException ( new IllegalArgumentException ( "Attribute<seq2seq4repair_space>cannot<seq2seq4repair_space>be<seq2seq4repair_space>null" ) , ( ( "Cannot<seq2seq4repair_space>invoke<seq2seq4repair_space>a<seq2seq4repair_space>setter<seq2seq4repair_space>of<seq2seq4repair_space>" + ( dClassName ) ) + "<seq2seq4repair_space>with<seq2seq4repair_space>null<seq2seq4repair_space>attribute" ) ) ; } String name = attribute . getName ( ) ; Object value = attribute . getValue ( ) ; if ( name == null ) { throw new RuntimeOperationsException ( new IllegalArgumentException ( "Attribute<seq2seq4repair_space>name<seq2seq4repair_space>cannot<seq2seq4repair_space>be<seq2seq4repair_space>null" ) , ( ( "Cannot<seq2seq4repair_space>invoke<seq2seq4repair_space>the<seq2seq4repair_space>setter<seq2seq4repair_space>of<seq2seq4repair_space>" + ( dClassName ) ) + "<seq2seq4repair_space>with<seq2seq4repair_space>null<seq2seq4repair_space>attribute<seq2seq4repair_space>name" ) ) ; } MethodUnion mu = ( ( MethodUnion ) ( dynamicProps . get ( name ) ) ) ; if ( ( mu != null ) && ( ( mu . writeMethod ) != null ) ) { Object [ ] o = new Object [ 1 ] ; Class [ ] params = mu . writeMethod . getParameterTypes ( ) ; <START_BUG> if ( ( params [ 0 ] ) == ( Priority . class ) ) { <END_BUG> value = OptionConverter . toLevel ( ( ( String ) ( value ) ) , ( ( Level ) ( getAttribute ( name ) ) ) ) ; } o [ 0 ] = value ; try { mu . writeMethod . invoke ( layout , o ) ; } catch ( Exception e ) { LayoutDynamicMBean . cat . error ( "FIXME" , e ) ; } } else { throw new AttributeNotFoundException ( ( ( ( "Attribute<seq2seq4repair_space>" + name ) + "<seq2seq4repair_space>not<seq2seq4repair_space>found<seq2seq4repair_space>in<seq2seq4repair_space>" ) + ( this . getClass ( ) . getName ( ) ) ) ) ; } } }

Fix:
if ( ( params [ 0 ] ) == ( Level . class ) ) {